#include<stdio.h>
#include<string.h>

int main()
{
	char s[101];
	//int arr[128] = { 0 };
	while (gets_s(s))
	{
		//char s[101];
		int arr[128] = { 0 };
		//printf("%s\n", s);
		int len = strlen(s);
		for (int i = 0; i < len; i++)
		{
			if (arr[s[i]] == 1)
				continue;
			if (arr[s[i]] == 0)
				arr[s[i]]++;
			if (arr[s[i]] == 1)
			{
				int index = (int)s[i];
				printf("%c", index);
			}
		}
		printf("\n");
	}
	
}